Drafting machine



May 21, 1946. A. L. BAKER 2,400,133

I i DRAFTING MACHINE Filed Nov; 9, v19:59 s sheets-sheet i )LE mvENToR9- b 1u/sra? afs/eff? f BY @man QW@ 8MM ATTORNEYs May 21, 1946. A. L.BAKER DRAWING MACHINE Filed Nov. 9, 1959 3 Sheets-Sheet 2 INVENTRALL/STER 54x59 BY @JCM ML ATTORNEYS May 21, 1946. l A, L. BAKER52,400,733

DRAFTJNG MACHINE Filed Nov, 9, 1939 :s sheetssheet s.

ALL/$727? L. 3H/(ER BY @im emv, ,21 www@ ATTORNEYS Patented May 21, 1946DRAFTING MACHINE Allister L. Baker, Hoboken, N. J., assignor to Keufel &Esser Company, Hoboken, N. J., a corporation of New Jersey ApplicationNovember 9, 1939, Serial No. 303,558

6 Claims. (Cl, 33--79) This invention relates generally to parallelmotion drafting devices of the kind in which the several tools which thedraftsman handles most frequently are embodied, in principle, in oneunit to obviats the necessity of a draftsman reaching about for arequired tool and thereby enabling the draftsman tol keep his attentionconcentrated Y directly upon. the drawing.

Drafting devices of this character are common in which adjacent ends oftwo arms are pivoted together, the free en-d of one arm being secured tothe remote side of a drafting board while the free end of the other armis provided with a. head comprising a protractor and straight edgeswhich are in fixed angular relation to move about the center of theprotractoras an axis. Such straight edges have heretofore been soassociated with the protractor as to be set and locked at any angle ofthe protractor or to be automatically stopped at predeterminedintervals, but the instrumentalities effecting the setting of thestraight edges with respect to readings on the protractor have beencharacterized by difficulty in the manual actuation of ti locking devicebec us f i e a' e of lts mac tion. Each of the arms I2 1s illustrated 1nFigure cessibility.

One object of the present invention is a drafting device of thecharacter described, wherein the locking devices for the straight edgesare readily accessible for manipulation without moving the hand from theknob on the protractor head.

The invention also has for its object locking and stop ymechanism forthe protractor which may conveniently lbe actuated by the thumb of thehand manipulating the protractor to the desired ..1 i

relative position. in carrying this aspect of the invention into edect,a single control lever is preferably provided on the knob of the head,which is movable in one direction to permit the scales to move freely toany angular position but which, on release, will effect locking of theyprotractor at the nearest even predetermined position.

Another object of the invention is to free the protractor from controlbythe latching mechanism so that it may be freely moved from oneposition to the other by manipulation of the knob, the release beingeffected by the thumb, say, without removing the hand from the knob. Tothis end, provision is made for retaining the control lever in the headin latch releasing position.

The invention also resides in the details of construction by which adrafting device is made practical from the standpoint of ease andconvenience in manufacture and durc'bility and facility in use.

These and other objects of the invention and the means for theirattainment will bemore apparent from the following detailed description,taken in connection with the accompanying drawings illustrating oneembodiment by which the invention may be realized, and in which:

Figure l is a view showing the head of the drafting device of thisinvention, in vertical section;

Figure 2 is a view looking from above and showing the drafting head ofFigure l, parts being broken away to illustrate particularly the lockingdevice of this invention;

Figure 3 is a detail view; and y Figure 4 is a View showing the head ofthe drafting device, looking from below in Figure l.

Referring rst to Figure l, it will be noted that a knob I0 is turnablerelative to the pulley 2i at 'the end of the arm l2 to adjust theposition of straight edges carried in the frameV member I4 with respectto the pulley which is, as will be understood, a member relatively xedin orienta- 2 as consisting generally of a pair of spaced channeledshaped connecting members, respectively, comprised of the side walls oranges I5, I6 connected by a top wall Il. The ends of the arm I2 areformed with a semi-cylindrical end wall I8 which is a continuation ofthe outside ange I5 and a flange I9 connecting the inner flange IE atthe free end. The space defined by the'walls i3 and I9 may receive apulley 2I. Obviously the arms may assume any convenient structuralshape.

The semi-cylindrical end of the arm IZ is provided, substantiallyconcentric with the end wall I8, with a downwardly extending cylindricalboss or flange .22 and an axial aperture .or bore 24. Within this wall22 is mounted an anti-friction device, not shown, in which turns thejournal 25 of the pulley 2i. The journal 25 is formed with a bore 26 forthe pivot pin 28 which is connected at its upper end to the hand knob leand at its lower end is fast as by screws 2% in the frame member I4supporting the straight edges.

The knob I0 is recessed, as at 3l and receives a generally rectangularframe or box comprised of the top wall 32, end walls 33, 31S and bottomwall 35. The top wal1'32 is formed with a threaded aperture 36 receivinga screw 3l by which the knob I0 and frame 32, 35 are united. The bottomWall 35 is apertured, as at 39, to receive the cylindrical surface MI onthe pivot pin 28, the latter being clamped to the frame by nut 4|. Thus,when the knob is turned, the pivot pin 28 turns with it and turns thestraight edge frame |4.

'I'he straight edge frame member I4 lies in parallel relationship to thebottom of the pulley 2| with respect to which it is capable of turning Yand is,` conveniently although not necessarily, in

substantially the shape of a, triangular plate, as

shown in Figure V4, having an arm 43 extending in one direction and anarm 44 extendingY in a direction generally perpendicular thereto, themarms `43 and 44 being adapted to receive the straight edges, as will beunderstood. The frame 14 thus turns with the knob It and also is abie toturn with respect to the pulley 2|, latch means,

being provided to nx the straight edge frame I4 to the pulley 2| inmantaining the proper rela,-

tionship with the lines on the drawing.

The pulley 2| is provided with a groove 46 forY the endless belt 41 andis rabbeted lin its lower peripheral edge, as at 48. Disposed withinrtherabbeted portion 48 is an annular plate 5D formed in its periphery atpredetermined" intervals with wan t4 of the frame sz-st, This sus@ '12is v Y 15.

I0 so that the operator may, in grasping the' knob, actuate the member12 by Vthe Vthumb of Ythe same hand. `The member 12 conveniently Yslidesin a passage 13in the knob mand is free to move in the open sidebetweenjwall 33Y and eccentrically connected with shaft'. As shown,

- it isi pivoted atits inner end to an arm 15 secured locking recesses5| (Figure 2). Since the pulley 2| is relatively iiXedl in orientationand the latching plate 5|) is immovably carried thereon, said latchingplate -is also relatively fixed in orienta` tion. The recesses 5| bear adeiiniterelation t0 the graduations on the protractor 52 whereby, inconjunction with cooperating locking devices 5|, 53 about to bedescribed, the straight edges Ymay be fixed with respect to theprotractoi" 52 4at Ypredetermined successive intervals, such as everyfteen degrees, with respect to an index as determined, say, on a Vernierplate54 carried with the frame |4. As a matter of fact, the position ofthe protractor 52'i's determined by the position of the pulley 2| andthe band 41. The frame |4 Ywhich carries the straight edges is movedrelative to the protractor and the angular position of the straightedges with respect to lines on the draw-l ings yis determined by theengagement of the cooperating locking device/or latch 53 (Figure 4) in apredetermined -recess V5|, it beingr contem` plated that thiscooperating locking device shall,

in some circumstances, automaticallysnap into a recess 5| and thuspermita ready location of` the straight edges through predetermined angles,such as angles of 15 or multiples thereof. Thus, the straight edgecarrying frame I4 may be .said to be relatively xed with respect to thelatching plate 55. Y

The cooperating latching member is shown in greater detail in Figures 2and 4 as an angularly shaped levers 53 formed with a detent 56 at itsone end which is shaped as to enter into and position itself in one oftherecesses 5|. The other extremity 51 of the arm 53 is formed with anaperture 58 for reception on a pin B0 mounted on the triangular plateI4. The latching'lever 53 is normally urged toward the latching plate 50by pin 62 on one end of a link 63 beneath the lower surface Yof thestraight edge plate I4. is held to the bottom of the plate 4 by theenlarged head of a screw 19 threaded into plate I4 and passing through'aslot 8l! inthe link 63. VThe link is pivoted as at G4' to one end E5of'a lever |55, 55 and held, as by nut 61, on the lower fend Movement ofthe lever 65, 55 in a clockwise di,- rection, as viewed in Figure 4,under the influence of the spring 69 will tend to urge the detent 56 ofthe latch member 53 into a'recess 5| of the on the squared end 15 ofshaft 58, on which it is Vheld by a nut 11. Y.

The plunger 'I2 is preferably pivotally connecte ed to the arm 15 as bythe pin, the head of which is shown at 18, sothat the plunger may swingthrough an arc about pin 18. The slot in which the plunger 12reciprocates is of a dimension, circumferentiallyfsuncient to permit theplunger toA assume the full line position of Figure 2 and also'thedotted Yline position in that figure. In the full line positiontheplunger 12 may be reciprocated to actuate the latch.-

To retain the latch in inoperative positionyas shown in dotted lines inFigure 2, that is, so that the straight edge plate I4 may be rotatedfreely,A v

the plunger 12 is formed With a recess or 'slot Y8| and a portion of theedge of Wall 34 is cut out,V Y and preferablydisplaced, as a tongue 14.Then, when the plunger is pressed inwardly and moved inacounter-clockwise direction, as viewed in Figure 2, the tongue 14 entersthe notch 8| and Y retains the plunger Yin latch releasing position.

In order to holdthe straight ed-ges'at points intermediate theyregistering positions Vof the notches 5|, a clamping ylever 82 L,(Figures 2 and 3) is provided; This lever is formed with a threaded`aperture 33 in one end, to serve as a nut which is threaded on to athreaded portion 84 of the pin 28. When the clamping lever is turned, itbearson a thrust bearing 85 and serves to draw upwardly the pin 28 andclamp or draw the straight edge carrying frame |4 or an element i 81 ofthe pivot pin 28 by which the straight edge supporting plate is Xed tothe pivotr pin against the pulley'to frictionally hold the straightYedges at any desired angle. 'Y Y Heretofore, the actuating lever forthe; latch controlling the position of the straight edgesY has 'beendisposedat a relatively low point with respect to the operating knob andproximate the plane of the straight edges. This has 'been inconvenientand it has generally required two hands to manipulate. By the presentinvention,

it will be seenr that the draftsman can "readily release the catch whilehis .hand is on the knob Link sa I0 and turn the frame |4, and thestraight edges carried thereby, tothe desired graduation on theprotractor, whenhe can again Arelease the plunger` 12 and permit thespring 69 to move the latch into a selected recess 5| Again, when he hasreleased the latch he canmove the plunger intov engagement withV theretaining member 14 to retain the latch in oiT position so that theprotractor may be freely moved to different angular positions. n Y

Various modications will occur to those skilled in the art in thecomposition, connguration and disposition of the component elementsgoing to make up the invention as a Vwhole as well as ink 4 theselection and combination of features to accomplish the results sought,and no limitation is intended by the phraseology of the foregoingdescription or illustrations in the accompany drawings, except asindicated in the appended claims.

What is claimed is:

1. In a drafting machine head, in combination, a tubular pivot pinformed at its lower end with a flange, a pulley rotatable about thepivot pin and formed therebelow with an axial recess receiving ange, astraight edge frame secured to the flange, a latching plate secured tothe pulley above the straight edge frame, said straight edge frame beingformed with an aperture, a latch pivotally mounted on the frameproximate the aperture for coaction with the latching plate, a shaftwithin the tubular pivot pin, an arm on the shaft -below the frame, anda link connecting the arm with the latch for actuation thereof betweenlatched and unlatched position.

2. In a drafting machine head, in combination, a tubular pivot pinformed at its lower end with a flange, a pulley rotatable about thepivot pin and formed therebelow with an axial recess receiving theflange, a straight edge frame secured to the ange, a latching platesecured to the pulley above the straight edge frame, said straight edgeframe being formed with an aperture, a latch pivotally mounted on theframe proximate the aperture for coaction with the latching plate, ashaft within the tubular pivot pin, a lever arm mounted intermediate theends thereof on the lower end of the shaft, and a spring extendingbetween one arm of the lever and the frame.

3. In a drafting machine head, in combination, a tubular pivot pinformed at its lower end with a flange, a pulley rotatable about thepivot pin and formed therebelow with an axial recess receiving theflange, a straight edge frame secured to the flange, a latching platesecured to the pulley above the straight edge frame, a latch plvotallymounted on the frame for coaction with the latching plate, a shaftwithin the tubular pivot pin, a lever arm mounted intermediate the endsthereof on the lower end of the shaft, and a spring extending betweenone arm of the lever and the frame.

4.. In a drafting machine head, in combination, a tubular -plvot pin, apulley rotatable about the pivot pin, a straight edge frame secured tothe pivot pin, a latching plate secured to the pulley above the straightedge frame, said straight edge frame being formed with an aperture, alatch pivotally mounted on the frame proximate the aperture for coactionwith the latching plate, a shaft within the tubular pivot pin, a bellcrankk lever mounted intermediate the ends thereof on the lower end ofthe shaft, one free end of said lever being shorter than the other, aspring extending from the longer arm of the lever to the frame, and alink extending from the shorter arm of the lever to the latch to actuatethe same.

5. In a drafting machine head, in combination, a tubular pivot pin, apulley rotatable about the pivot pin, a straight edge frame secured tothe pivot pin, a latching plate secured to the pulley above the straightedge frame, said straight edge frame being formed with an aperture, alatch pivotally mounted on the frame proximate the aperture for coactionwith the latching plate, a shaft within the tubular pivot pin, a framehaving at least one vertical edge carried by the pivot pin, an arm onthe shaft within the frame, a plunger pivoted to the end of the arm,said pivoted plunger being formed with a notch so positioned as toengage the vertical edge in one position of the arm to retain the latchin open position.

6. In a drafting machine head, in combination, a tubular pivot pinformed at its lower end with a flange, Va pulley rotatable about'thepivot pin and formed therebelow with an axial recess receiving theflange, a straight edge frame secured to the flange, a latching platesecured to the pulley above the straight edge frame, said straight edgeframe being formed with an aperture, a latch pivotally mounted on theframe proximate the aperture for coaction with the latching plate, ashaft within the tubular pivot pin, a frame having at least one tonguecarried by the pivot pin, an arm on the shaft within the frame, aplunger pivoted to the end of the arm, said pivoted plunger being formedwith a notch so positioned as to engage the tongue in one position ofthe arm to retain the latch in open position.

ALLISTER L. BAER.

